Use of novel organoselenium compounds as pro-oxidizing agents their methods of preparation and pharmaceutical compositions and application thereof

ABSTRACT

Compounds represented by the following formula I: ##STR1## in which: R 1  to R 5  can have various meanings of which alkyl, substituted or non-substituted aryl, and m is equal to 0 or 1, X is selected from (CR 6  R 7 ) n  in which n=0 or 1, and CO are disclosed. These compounds are useful as anti-tumor drugs, especially with pro-oxidizing activity.

The present invention relates to the use of novel organoseleniumcompounds as pro-oxidizing agents, their methods of preparation andpharmaceutical compositions and application thereof.

PRIOR ART

The reactive oxygen entities (ROEs), such as, for example, thesuperoxide anion (O₂) and hydrogen peroxide (H₂ O₂), coming frommetabolism of oxygen, generated within the cell are under the control ofthe antioxidizing protection system. This system is composed inparticular of macromolecules with enzymatic activity such as superoxidedismutases (SOD), catalase and glutathione peroxidases, as well as smallmolecules with high reducing potential such as, for example,glutathione, vitamin E, vitamin C and lipoic acid. This antioxidizingsystem plays a central role in the prevention of <<oxidative stress>>and its deleterious consequences (1).

In normal physiological situations, an equilibrium between theproduction and the decomposition of these reactive oxygen entities(ROEs) already exists in the cell. If this fragile equilibrium becomesdurably disrupted under the influence of a physical stimulus (UV,ionizing radiation, . . . ), or an internal chemical stimulus(cytokines), or an external chemical stimulus (xenobiotics, cigarettes,. . . ) the production of these ROEs surpassing the antioxidizingprotection system, the cellular structures (membranes, mitochondria,DNA, . . . ) are destroyed. This phenomenon being able to leadirreversibly to cellular death if this imbalance attains a criticalthreshold. This general physiopathological mechanism has been proposedin a large number of diseases such as inflammatory diseases (see Ann.Rev. Physiol.; 1986, 48, 681-692 and Ann. Rev. Resp. Dis. 1989, 139,1553-1564), cardiovascular diseases (see Free Radic. Biol. Med.; 1994,16, 35-41), the genesis of certain cancers (see Science; 1983, 221,1256-1264 and Ann. Rev. Pharmacol. Toxicol.; 1985, 25, 509-528 as wellas Free Radic. Biol. Med.; 1994, 16, 99-109) as well as for thephenomenon of ageing.

The controlled generation of these ROEs has proved to be formidableweapon for the destruction of certain target cells such as tumor cells.The pharmocological concept consisting in the use of cytotoxic drugswhich generate reactive oxygen entities was implicitly bound to the modeof action of anti-cancer drugs such as, for example, bleomycin (see<<Bleomycin: chemical, biochemical and biological aspects >>; Hecht S.M. ed.; (1979); Springer Verlag, N.Y.; 24) whose target is DNA,anthracyclines (daunorubicin, daunomycin, . . . ) (see P. N. A. S.;1986, 83, 4514 and Biochem.; 1987, 26, 3776), mitomycin C and itsanalogues Int. J. Radiat. Oncol. Biol. Phys.; 1979, 5, 851),nitroimidazoles (misonidazole, pimonidazole, . . . ) (see Int. J.Radiat. Oncol. Biol. Phys.; 1992, 22, 643 and 649) amongst others.

Furthermore, it has been demonstrated that the toxicity oforganoselenium compounds of the selenol and/or diselenide type is in alarge part due to the catalytic reduction of oxygen giving superoxideand hydrogen peroxide (see Arch. Biochem. Biophys.; 1992, 296, 328-336).

On the other hand, various benzisoselenazolines and benzisoselenazineswere described by the Applicant in the prior patent application Ser. No.2 718 441 which possess a therapeutic activity as antioxidizing andanti-inflammatory agents. The substituents on the benzene ring canoccupy any of the positions and no compound described possesses anaromatic substituent in a position ortho to the selenium, with theexception of one sole compound which possesses a nitro substitution inortho combined with a dimethyl substitution in benzylic position.

One of the aims of the present invention is to conceive organoseleniumcompounds possessing a catalytic pro-oxidizing activity, i.e. anactivity generating reactive oxygen entities which can destroy a targetcell, in particular a pathogenic cell, such as a tumor cell.

These compounds must be able to penetrate the interior of the targettissues or cells, they must be water-soluble at active concentrationsand must efficiently reduce oxygen to give toxic by-products.

These aims are attained by this invention which consists in the designof novel organoselenium derivatives whose pro-oxidizing and cytotoxicactivities as well as their methods of preparation are described.

It is completely surprising, in the framework of the present invention,that the organoselenium derivatives possess a pro-oxidizing activity,given that the organoselenium compounds described in the priorapplication of the applicant, FR-A-94 04107, which had been shown topossess an anti-oxidizing activity and had been tested as such. Fromthis fact, although it had been described that the radicals R¹ and R²could stand for --NO₂, in general, their position on the benzene ringwas not specified and only one example described the synthesis of aderivative bearing a nitro group in the position ortho to the seleniumon the benzene ring. This compound was claimed as a novel compound, butwas inactive as an anti-oxidizing agent.

DESCRIPTION OF THE INVENTION

The aim of the present invention is:

1) to solve the novel technical problem consisting in providing novelorganoselenium derivatives possessing excellent pro-oxidizing andcytotoxic activities, which can thus constitute a valuable activeingredient in the framework of pharmaceutical compositions;

2) to solve the novel technical problem, set forth above, with asolution which also provides a method for the preparation of thesecompounds which is relatively easy to carry out;

These aspects of the technical problem described above aresimultaneously solved by the present invention by a simple solution,with a preparation method which is relatively easy to carry out andwhich gives good yields.

In a first aspect, the present invention provides novel organoseleniumcompounds of the following general formula(I): ##STR2## wherein: R¹ isselected from a group consisting of: hydrogen; C₁ -C₆ alkyl; ar(C₁-C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identicalor different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo (C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical ordifferent groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂ ; --CONR⁸ R⁹ ;--(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R² is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R³ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁴ is selected from the group consisting of: --NO₂ ; --NO; --CN; --COOR⁹; --SO₃ R⁹ ; --CONR⁹ R¹¹ and --SO₂ NR⁹ R¹¹ ;

R⁵ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; --(CH₂)_(p) Vect; --N⁺R¹¹ ₃ Y⁻ ; --SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ;

X is selected from the group consisting of: (CR⁶ R⁷)_(n) ; and CO;

R⁶ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁷ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁸ is selected from the group consisting of: C₁ -C₆ alkyl; ar(C₁-C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identicalor different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical ordifferent groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; heteroaryl; heteroaryl substituted by one or moreidentical or different groups selected from: C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect;

R⁹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect;

R¹⁰ is selected from the group consisting of: hydrogen; --N⁺ R¹¹ ₃ Y⁻ ;--SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ;

R¹¹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl;

Vect= ##STR3## W represents either a simple linkage with --(CH₂)_(p) --,or a heteroatom such as O, S or N, bound to --(CH₂)_(p) --;

Y⁻ represents the anion of a pharmaceutically acceptable acid;

Z⁺ represents the cation of a pharmaceutically acceptable base;

n=0, 1;

m=0, 1;

p=2 to 10;

and their salts of pharmaceutically acceptable acids or bases;

with the proviso that there can not be more than one Vect substituentwithin each molecule of the general formula I.

With the further proviso that:

When R⁴ is --NO₂, then at least one of R² and R³ is other than methyl.

In the framework of the description and the claims:

the term <<lower alkyl group>> or <<C₁ -C₆ alkyl group>> means linear orbranched groups containing 1 to 6 carbon atoms;

the term <<substituted>>, as applied to the aryl or aralkyl groups,means that these are substituted in the aromatic portion by one or moreidentical or different groups selected from: C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H; --CO₂ --(C₁ -C₆)alkyl; or by one or more hydrogenatoms;

when R⁴ represents --COOH, --SO₃ H, the invention also covers theaddition salts of a pharmaceutically acceptable base.

Amongst the pharmaceutically acceptable acids, cited in a non-limitingway, are: hydrochloric, hydrobromic, hydroiodic, sulfuric, tartaric,methanesulfonic, trifluoromethanesulfonic acid, etc. . . .

Amongst the pharmaceutically acceptable bases, cited in a non-limitingway, are: sodium and potassium hydroxides, alkali metal oralkaline-earth metal carbonates or organic bases such as triethylamineor arginine, etc. . .

In a second aspect, the present invention relates to the use oforganoselenium compounds of the following general formula (IA): ##STR4##wherein: R¹ is selected from a group consisting of: hydrogen; C₁ -C₆alkyl; ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one ormore identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R² is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R³ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁴ is selected from the group consisting of: --NO₂ ; --NO; --CN; --COOR⁹; --SO₃ R⁹ ; --CONR⁹ R¹¹ and --SO₂ NR⁹ R¹¹ ;

R⁵ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; --(CH₂)_(p) Vect; --N⁺R¹¹ ₃ Y⁻ ; --SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ;

X is selected from the group consisting of: (CR⁶ R⁷)_(n) ; and CO;

R⁶ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁷ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁸ is selected from the group consisting of: C₁ -C₆ alkyl; ar(C₁-C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identicalor different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical ordifferent groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; heteroaryl; heteroaryl substituted by one or moreidentical or different groups selected from: C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect;

R⁹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect;

R¹⁰ is selected from the group consisting of: hydrogen; --N⁺ R¹¹ ₃ Y⁻ ;--SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ;

R¹¹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl;

Vect= ##STR5## W represents either a simple linkage with --(CH₂)_(p) --,or a heteroatom such as O, S or N, bound to --(CH₂)_(p) --;

Y⁻ represents the anion of a pharmaceutically acceptable acid;

Z⁺ represents the cation of a pharmaceutically acceptable base;

n=0, 1;

m=0, 1;

p=2 to 10;

and their salts of pharmaceutically acceptable acids or bases;

with the proviso that there can not be more than one Vect substituentwithin each molecule of the general formula IA;

as a pro-oxidizing agent.

The invention also covers the methods of therapeutic treatmentcorresponding to this use, as is well understandable for a personskilled in the art.

In an advantageous embodiment, the present invention relates to the useof the above-mentioned compounds of general formula IA for themanufacture of a pharmaceutical composition with pro-oxidizing activity,in particular in the treatment of cancers in which an intracellularoverproduction of cytotoxic reactive oxygen entities contributes tofunctional alterations in the corresponding tumor cells.

In these cancerous pathologies, the active ingredient can beadministered via the oral, rectal or topical route, or even byintramuscular or intravenous injection.

In another advantageous embodiment, the organoselenium derivative of theabove-mentioned general formula (IA) is present in an amount in therange 0.01% to 5% by weight with respect to the total weight of thefinal composition, preferably in the range 0.1% to 1% by weight.

In another advantageous embodiment, the present invention relates to theuse of the composition in the form of unit dose which may comprise 1 mgto 500 mg of the organoselenium derivative of the above-mentionedgeneral formula (IA), optionally in a pharmaceutically acceptableexcipient, vehicle or support.

In a third aspect, the present invention also provides a pharmaceuticalcomposition, in particular with pro-oxidizing activity, characterized inthat it comprises, as active ingredient, at least one organoseleniumderivative of the following general formula (IA): ##STR6## wherein: R¹is selected from a group consisting of: hydrogen; C₁ -C₆ alkyl; ar(C₁-C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identicalor different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical ordifferent groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂ ; --CONR⁸ R⁹ ;--(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R² is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R³ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁴ is selected from the group consisting of: --NO₂ ; --NO; --CN; --COOR⁹; --SO₃ R⁹ ; --CONR⁹ R¹¹ and --SO₂ NR⁹ R¹¹ ;

R⁵ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; --(CH₂)_(p) Vect; --N⁺R¹¹ ₃ Y⁻ ; --SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ;

X is selected from the group consisting of: (CR⁶ R⁷)_(n) ; and CO;

R⁶ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁷ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;--COR⁸ ; --COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;

R⁸ is selected from the group consisting of: C₁ -C₆ alkyl; ar(C₁-C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identicalor different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical ordifferent groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆-alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and--CO₂ --(C₁ -C₆)alkyl; heteroaryl; heteroaryl substituted by one or moreidentical or different groups selected from: C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect;

R⁹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect;

R¹⁰ is selected from the group consisting of: hydrogen; --N⁺ R¹¹ ₃ Y⁻ ;--SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ;

R¹¹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl;ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or moreidentical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted byone or more identical or different groups selected from C₁ -C₆ alkyl,trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆-alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl;

Vect= ##STR7## W represents either a simple linkage with --(CH₂)_(p) --,or a heteroatom such as O, S or N, bound to --(CH₂)_(p) --;

Y⁻ represents the anion of a pharmaceutically acceptable acid;

Z⁺ represents the cation of a pharmaceutically acceptable base;

n=0, 1;

m=0, 1;

p=2 to 10;

and their salts of pharmaceutically acceptable acids or bases;

with the proviso that there can not be more than one Vect substituentwithin each molecule of the general formula IA.

In a fourth aspect, the invention covers a method of preparation of anorganoselenium compound of the above-mentioned general formula IA,characterized in that it comprises the following essential steps (seeScheme 1):

a) preparing or using a correctly substituted3-nitro-2-halophenylacetonitrile derivative,

then depending on the series considered:

either

b1) hydrolyzing the nitrile derivative to an amide derivative,

c1) transforming this amide derivative into an amine derivative by atransposition reaction using usual methods,

d1) N-acylating this amine derivative using usual procedures;

e1) reacting the latter with a nucleophilic selenium derivative, whichmay be generated in situ, in the presence of a copper salt, in a polarorganic solvent, in order to produce the correspondingbenzisoselenazoline derivative,

f1) hydrolysing the heterocyclic derivative thus obtained, if necessary,to the corresponding amine in order to be N-alkylated if necessary usingusual procedures;

g1) finally, oxidizing the derivative thus obtained if necessary usingusual procedures;

or

b2) reducing the nitrile derivative to an amine derivative with the aidof a reducing agent such as, for example, borane in an ethereal solventsuch as, for example, tetrahydrofuran,

c2) N-acylating the amine compound using usual procedures;

d2) reacting the amine compound with a nucleophilic selenium derivative,if necessary generated in situ, in the presence of a copper salt, in apolar organic solvent, in order to produce the correspondingbenzisoselenazine derivative,

e2) hydrolyzing the heterocyclic derivative thus obtained if necessaryto the corresponding amine in order to be N-alkylated, if necessary,using usual procedures;

f2) finally, oxidizing the derivative thus obtained if necessary usingusual procedures;

or

b3) mono- or di-alkylating the nitrile derivative to give an aminederivative,

c3) N-acylating this amine compound using usual procedures;

d3) reacting this amine compound with a nucleophilic seleniumderivative, if necessary generated in situ, in the presence of a coppersalt, in a polar organic solvent, in order to produce the correspondingbenzisoselenazine derivative,

e3) hydrolyzing the heterocyclic derivative thus obtained if necessaryto the corresponding amine in order to be N-alkylated if necessary,using usual procedures;

f3) finally, oxidizing the derivative thus obtained if necessary, usingusual procedures;

It should be noted that in the framework of the invention, theN-acylation of the amine compound is carried out before proceeding withthe reaction with the nucleophilic selenium derivative, since thisimproves the yield of this synthesis in an unexpected manner.

Another implementation of this procedure is characterized in that thenucleophilic selenium compound is preferably a selenocyanate salt suchas, for example, potassium selenocyanate which can be:

either generated in situ from elemental selenium (Se⁰) and a cyanidesalt such as, for example, potassium cyanide,

or added to the reaction medium as it is.

Yet another particular implementation of the method is characterized inthat the copper salt can be a cuprous salt (Cu¹), such as, for example,cuprous iodide.

Another implementation of this method is characterized in that the polarorganic solvent is preferably dimethylformamide.

Another implementation of this method is characterized in that theoxidizing agent which is optionally used can be a peracid, such asmetachloroperbenzoic acid, or hydrogen peroxide.

Other aims, characteristics and advantages of the invention will becomeclear from the following description which is made with reference tonon-limiting examples which are given simply by way of illustration andin no way limit the scope of the invention. In the examples, all thepercentages are given as percentages by weight unless stated otherwise.Furthermore, in all the examples, the temperature is expressed indegrees Celsius and the reaction takes place at atmospheric pressure andat room temperature unless stated otherwise.

DESCRIPTION OF FIGURES

FIG. 1 represents a curve obtained in a test which demonstrates theprooxidizing activity of the compound of Example 1, namely3,3-dimethyl-7-nitrobenzisoselenazoline, characterized by theconsumption of the cofactor NADPH as a function of time, expressed inminutes, along the abcissa, and by the measured optical density,expressed in arbitrary units measured at 340 nm, on the ordinate. Thecurve starts at an optical density (O.D.) of 1.5 arbitrary units at timeequal to 0 minutes. The control values are the values obtained in theabsence of the compound of Example 1.

FIG. 2 represents the curve of reduction of ferric cytochrome C by acompound of the invention of Example 1, in the presence of variouseffectors. The concentration of ferric Cytochrome C is expressed on theordinate in micromoles per litre (10⁻⁶ M), as a function of time,expressed in minutes, along the abcissa.

In FIG. 2, the compound of the invention of Example 1 (which is also thesubject of the test of FIG. 1), is in the presence of various effectors,as follows:

a) the curve with empty circles has been obtained with the compound ofthe invention of Example 1 used alone;

b) the curve with full squares is obtained with the compound of theinvention of Example 1 together with reduced glutathione (GSH) as theeffector, being used as a reference;

c) the curve with full circles is obtained with the compound of theinvention of Example 1 together with GR NADPH as the effector, GR NADPHbeing the glutathione reductase enzyme in the presence of its cofactorNADPH alone;

d) the curve with empty squares is obtained with the compound of theinvention of Example 1 in the presence of GSH;

e) the curve with full triangles is obtained with the compound of theinvention of Example 1 in the presence of both GR NADPH and GSH; and

f) the curve with empty triangles is obtained in the presence of thefull combination of the effectors GSH, GR NADPH and the compound of theinvention of Example 1.

FIG. 3 shows a histogram representing, on the ordinate, the percentagemortality of the HL60 tumor cells after 24 hours incubation with thecompound of the invention of Example 1, as a function of concentrationof the compound of the invention of Example 1, expressed in micromolesper litre (μM), along the abcissa. This histogram is obtained from thetest of Example 14. The bars with the vertical strokes represent acellular viability test with the colorant MTT, and the black bars withwhite dots represent a viability test by coloration with the colorantproduct trypan blue (TB).

FIG. 4 represents a curve, similar to that of FIG. 3, after 48 hours ofincubation.

FIG. 5 shows a histogram representing the results of toxicity of thecompound of the invention of Example 7, step 1, on breast cancer tumorcells (MCF-7). The various concentrations of the compound of theinvention of Example 7, step 1, are expressed along the abcissa inmicromoles per litre, and the percentage mortality of these tumor cellsis expressed on the ordinate. Black bars represent the toxicity after 24hours of incubation, whereas white bars represent the toxicity after 48hours of incubation.

FIG. 6 shows a histogram representing the same test of toxicity as thatshown in FIG. 5, but with the compound of the invention of Example 4.

FIG. 7 shows yet another histogram representing the same test oftoxicity as those of FIGS. 5 and 6, only this time with the compound ofthe invention of Example 7, step 1.

FIG. 8 shows yet another histogram representing the same test oftoxicity as those of FIGS. 5 to 7, obtained this time with the compoundof the invention of Example 1.

EXPERIMENTAL SECTION

All reactions have been carried out in an inert nitrogen atmosphereunless otherwise stated.

Mass spectra have been recorded on a Nermag R10-10B instrument.Ionisation used either electron impact (EI) at 70 electron-volts, orchemical ionisation (CI) in terbutane.

¹ H and ¹³ C NMR spectra were recorded on a Varian Gemini-200instrument. Chemical shifts are expressed in ppm with respect totetramethylsilane. Multiplicities are expressed as follows: <<s>> for asinglet, <<br s>> for a broad singlet, <<d>> for a doublet, <<t>> for atriplet, <<q>> for a quadruplet and <<m>> for a multiplet.

Melting points (M. Pt.) were recorded on a Gallenkamp instrument and areuncorrected.

Purification by liquid column chromatography was carried out usingMerck® Si 60 F₂₅₄ silica gel.

I. EXAMPLES OF SYNTHESIS OF COMPOUNDS WITH FORMULA IA Example 13,3-Dimethyl-7-nitrobenzisoselenazoline

Step 1. Preparation of 2-bromo-3-nitrobromomethylbenzene.

To a mixture of 2-bromo-3-nitrotoluene (6.48 g, 30 mmol) andN-bromosuccinimide (5.34 g, 30 mmol) in 100 ml of CCl₄ is added2,2'-azobis(2-methylpropionitrile) (AIBN, 300 mg, 1.8 mmol). The mixturethus obtained is heated under reflux for 32 hours and then cooled toroom temperature. The solid is filtered and rinsed with CCl₄. Thefiltrate is evaporated to dryness to give a slightly yellow oil (10.1g). Analysis of the ¹ H NMR spectrum of this crude product indicatesthat it is a mixture of the expected compound, the dibrominated productand the starting product in a proportion of 57:10:33.

The crude product is used directly in the following step.

Step 2. Preparation of 2-bromo-3-nitrophenylacetonitrile.

The crude brominated product obtained above (10.1 g) is taken up with 75ml of methanol. Sodium cyanide (1.47 g, 30 mmol) is added in oneportion. The mixture is stirred at room temperature for 20 hours. Afterthe evaporation of the solvent, the residue is taken up with 30 ml ofCH₂ Cl₂ and 20 ml of water. The organic phase is separated and theaqueous phase is extracted with CH₂ Cl₂. The combined organic phases arewashed with a saturated aqueous solution of NaCl, dried over MgSO₄ andevaporated. The solid residue is triturated with methanol and thenfiltered and rinsed to give a first batch of the desired compound (1.93g). The filtrate is concentrated and then triturated with a mixture ofethyl acetate and cyclohexane (1:3). Filtration and rinsing with thesame mixture of solvents provide a second batch of the expected compound(0.85 g). The filtrate is again concentrated. The residue is purified bysilica gel column chromatography (eluent: CH₂ Cl₂ :cyclohexane, 1:1) togive a third batch of the desired compound. The totality of the isolatedproduct is 3.90 g (54% in two steps from 2-bromo-3-nitrotoluene).

M. Pt. 116° C. ¹ H NMR: 3.94 (s, 2H), 7.53 (t, 1H, J=7.9 Hz), 7.72 (dd,1H, J=1.4, 7.9 Hz), 7.77 (d, 1H, J=7.9 Hz).

Step 3. Preparation of 2-(2-bromo-3-nitrophenyl)-2-methylpropionitrile.

A suspension of NaH (3.17 g, 60% dispersion in mineral oil, 79.2 mmol)in 70 ml of anhydrous DMF is cooled to -5° C. To this suspension isadded a solution of 2-bromo-3-nitrophenylacetonitrile (7.95 g, 32.9mmol) and iodomethane (8.2 ml, 131.7 mmol) in 30 ml of anhydrous DMF.The reaction medium is stirred at -5° C. for 0.5 hours, at roomtemperature for 0.5 hours, and then poured into 200 ml of water. Themixture is extracted with ethyl acetate. The combined organic phases arewashed with brine, dried over MgSO₄ and evaporated. The solid residue(10.93 g) essentially contain the expected product and is used directlyin the next step. It can be purified by recrystallization from a mixtureof solvents (EtOAc:cyclohexane, 1:3).

M. Pt. 94.5° C. ¹ H NMR: 1.90 (s, 6H), 7.50 (t, 1H, J=8.0 Hz), 7.56 (dd,1H, J=2.5, 8.0 Hz), 7.66 (d, 1H, J=2.5, 8.0 Hz).

Step 4. Preparation of 2-(2-bromo-3-nitrophenyl)-2-methylpropionamide.

The 2-(2-bromo-3-nitrophenyl)-2-methylpropionitrile obtained above(10.93 g) is dissolved in 250 ml of absolute ethanol. To this solutionare successively added 120 ml of a saturated aqueous solution of K₂ CO₃and 120 ml of an aqueous solution of H₂ O₂ (50%). The mixture is stirredvigorously at room temperature for 22 hours. 300 ml of ethyl acetate and300 ml of water are added. The organic phase is separated and theaqueous phase is extracted with ethyl acetate. The combined organicphases are washed with brine to remove the H₂ O₂, dried over MgSO₄ andevaporated to provide the pure desired compound (8.5 g, 90% in two stepsfrom 2-bromo-3-nitrophenylacetonitrile) as a white solid.

¹ H NMR: 1.68 (s, 6H), 5.30 (br s, 1H), 5.72 (br s, 1H), 7.48 (m, 2H),7.65 (m, 1H).

Step 5. Preparation of 1-(2-bromo-3-nitrophenyl)-1-methylethylamine.

The 2-(2-bromo-3-nitrophenyl)-2-methylpropionamide (1.75 g, 6.1 mmol) ismixed with 100 ml of acetonitrile and 100 ml of water. To this mixtureis added in one portion [bis(trifluoroacetoxy)iodo]benzene (2.89 g, 6.7mmol). The reaction medium is stirred at room temperature for 24 hoursand then poured into 200 ml of water. The mixture is then extracted withmethyl tert-butyl ether. The combined organic phases are washed withbrine and then extracted with an aqueous solution of HCl (10%). Thecombined acidic solutions are washed with methyl tert-butyl ether and,after cooling, are neutralised with an aqueous solution of NaOH (35%).The mixture is extracted with methyl tert-butyl ether. The combinedorganic phases are washed with a saturated aqueous solution of NaCl,dried over MgSO₄ and evaporated to provide the expected amine (1.05 g,66%) as a slightly yellow oil.

¹ H NMR: 1.70 (s, 6H), 1.95 (s, 2H), 7.38 (m, 2H), 7.83 (m, 1H).

Step 6. Preparation of 3,3-dimethyl-7-nitrobenzisoselenazoline.

To a solution of 1-(2-bromo-3-nitrophenyl)-1-methylethylamine (10.85 g,41.9 mmol) in 150 ml of anhydrous DMF is added, at room temperature,KSeCN (6.04 g, 41.9 mmol). The mixture is stirred for 3 minutes toprovide a homogeneous solution. CuI (7.98 g, 41.9 mmol) andtriethylamine (17.5 ml, 125.8 mmol) are added successively. The reactionmedium is stirred at room temperature for 22 hours, then poured into 200ml of an aqueous solution of CuCN (6.2 g, 68.9 mmol). The mixture isextracted with ethyl acetate. The combined organic phases are washedwith brine, dried over MgSO₄ and evaporated to provide a red solid.Purification by silica gel column chromatography (eluent:EtOAc:cyclohexane, 1:2) allows one to obtain the desired product (8.45g, 78%) as a red solid.

M. Pt: 124° C. ¹ H NMR: 1.52 (s, 6H), 3.70 (br s, 1H), 7.26 (dd, 1H,J=1.4, 7.4 Hz), 7.35 (t, 1H, J=7.4 Hz), 8.14 (dd, 1H, J=1.4, 7.4 Hz).

Example 2 N-Acetyl-4,4-dimethyl-8-nitrobenzisoselenazine

Step 1. Preparation of 2-(2-bromo-3-nitrophenyl)-2-methylpropylammoniumtrifluoroacetate.

The 2-(2-bromo-3-nitrophenyl)-2-methylpropionitrile prepared accordingto step 3 of Example 1 (1.0 g, 3.7 mmol) is dissolved in 10 ml ofanhydrous THF. BH₃.THF (10 ml, 1.0 M solution in THF, 10 mmol) is added.The reaction mixture is maintained under reflux for 3 hours before beingcooled to room temperature. 12 ml of an aqueous solution oftrifluoroacetic acid (50%) is added dropwise. The mixture is heatedunder relux for 1 hour. The solvents and the trifluoroacetic acid areevaporated. The residue is redissolved in 20 ml of THF and evaporated todryness. A crude solid product is obtained which contains essentiallythe desired product and is used directly in the following acetylationstep.

Step 2. Preparation ofN-acetyl-2-(2-bromo-3-nitrophenyl)-2-methylpropylamine.

To a solution of the above crude ammonium salt dissolved in 10 ml ofanhydrous THF is added acetic anhydride (0.52 ml, 5.6 mmol).Triethylamine (2.0 ml, 14.4 mmol) is added dropwise at 0° C. The mixtureis stirred at room temperature for 1 hour, then evaporated to dryness.The residue is taken up with 20 ml of ethyl acetate. The organicsolution is washed with a saturated aqueous solution of NaCl, dried overMgSO₄ and evaporated. The residue is purified by silica gel columnchromatography (eluent: EtOAc:cyclohexane, 2:1) to provide the desiredamide (0.97 g, 83% in two steps from2-(2-bromo-3-nitrophenyl)-2-methylpropionitrile).

MS (EI): 316 (3), 314 (3), 235 (29), 72 (100). ¹ H NMR: 1.55 (s, 6H),1.91 (s, 3H), 3.91 (d, 2H, J=6.4 Hz), 5.16 (br s, 1H), 7.42 (m, 2H),7.58 (m, 1H).

Step 3: Preparation of N-acetyl-4,4-dimethyl-8-nitrobenzisoselenazine.

The N-acetyl-2-(2-bromo-3-nitrophenyl)-2-methylpropylamine (158 mg, 0.5mmol) is dissolved in 3 ml of anhydrous DMF. KSeCN (72 mg, 0.5 mmol) isadded. After 3 minutes of stirring at room temperature, CuI (95 mg, 0.5mmol) and triethylamine (0.21 ml, 1.5 mmol) are added. The mixtureobtained is heated at 100° C. for 18 hours, then poured into 8 ml ofwater. The mixture is then extracted with ethyl acetate. The combinedorganic phases are washed with brine, dried over MgSO₄ and evaporated.The red solid residue is purified by silica gel column chromatography(eluent: EtOAc:cyclohexane, 1:1) to provide the expected product (77 mg,49%) as a red solid.

M. Pt.: 127° C. MS (EI): 314 (72), 226 (100), 196 (24), 115 (30). ¹ HNMR (this solid exists in the form of a mixture two isomers A and B(60:40) in CDCl₃): Isomer A: 1.33 (s, 6H), 2.30 (s, 3H), 3.95 (s, 2H),7.38 (t, 1H, J=8.1 Hz), 7.82 (dd, 1H, J=1.3, 8.1 Hz), 8.28 (dd, 1H,J=1.3, 8.1 Hz). Isomer B: 1.39 (s, 6H), 2.22 (s, 3H), 3.60 (s, 2H), 7.34(t, 1H, J=8.4 Hz), 7.78 (dd, 1H, J=1.3, 8.4 Hz), 8.27 (dd, 1H, J=1.3,8.4 Hz).

Example 3 4,4-Dimethyl-8-nitrobenzisoselenazine

A solution of N-acetyl-4,4-dimethyl-8-nitrobenzisoselenazine (70 mg,0.22 mmol) of Example 2 dissolved in 1 ml of acetic acid and 1 ml ofconcentrated hydrochloric acid is heated under reflux for 20 hours. Thereaction mixture cooled to 0° C. is neutralized with an aqueous solutionof NaOH (10%), then extracted with ethyl acetate. The combined organicphases are washed with a saturated aqueous solution of NaCl, dried overMgSO₄ and evaporated. The residue is purified by silica gel columnchromatography (eluent: EtOAc:cyclohexane, 1:3) to provide the thedesired product (32 mg, 53%) as a yellow solid.

M. Pt.: 108° C. MS (EI): 272 (52), 226 (100), 196 (48), 115 (57). ¹ HNMR: 1.33 (s, 6H), 3.15 (br s, 1H), 3.29 (s, 2H), 7.27 (t, 1H, J=8.3Hz), 7,75 (dd, 1H, J=1.3, 8.3 Hz), 8.22 (dd, 1H, J=1.3, 8.3 Hz).

Example 4 N-acetyl-3,3-dimethyl-7-nitrobenzisoselenazoline

The 3,3-dimethyl-7-nitrobenzisoselenazoline described in Example 1 (130mg, 0.5 mmol) is treated with 1 ml of acetic anhydride and 1 ml ofpyridine at 60° C. for 1.5 hours. The mixture is then evaporated todryness. The residue is triturated with a mixture of ethyl acetate andcyclohexane (1:2). The red solid is filtered and rinsed to provide theexpected amide (140 mg, 93%).

M. Pt.: 197° C. MS (EI): 300 (21), 285 (25), 243 (100). ¹ H NMR: 1.80(br s, 6H), 2.32 (br s, 3H), 7.30 (br d, 1H, J=7.8 Hz), 7.42 (t, 1H,J=7.8 Hz), 8.20 (dd, 1H, J=1.2, 7.8 Hz).

Example 5N-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline.

Step 1. Preparation of 17β-acetoxy-7α-(oct-7-enyl)estr-4-en-3-one.

To a mixture of 8-bromo-1-octene (6.4 g, 33.5 mmol) and magnesium (0.8g, 33.3 mmol), is introduced 20 ml of anhydrous THF. A small crystal ofI₂ is added. The mixture is heated to initiate the reaction. Afterstirring for 0.5 hours, the mixture is heated under reflux for 1 hour,then diluted with 20 ml of anhydrous THF. It is then cooled to -40° C.CuI (1.90 g, 10.0 mmol) is added in one portion. A solution of6-dehydro-19-nortestosterone acetate (7.0 g, 22.3 mmol) in 25 ml ofanhydrous THF is added dropwise over 15 minutes. The reaction mixture isstirred at -40° C. for 2 hours. Acetic acid (2.0 ml, 35.0 mmol) isintroduced at -40° C. 100 ml of brine is then added at room temperature.The mixture is extracted with ethyl acetate. The combined organic phasesare washed with brine, dried over MgSO₄ and evaporated. The residue ispurified by silica gel column chromatography (eluent: EtOAc:cyclohexane,1:9) to provide firstly the 7α isomer (3.75 g, 39%) then the 7β isomer(2.15 g, 23%).

MS (EI) of 7α isomer: 426 (26), 315 (100). ¹ H NMR of 7α isomer: 0.82(s, 3H), 2.01 (s, 3H), 0.90-2.53 (m, 31H), 4.59 (dd, 1H, J=7.6, 8.8 Hz),4.90 (m, 1H), 4.96 (m, 1H), 5.76 (m, 1H), 5.80 (s, 1 H).

Step 2: Preparation of17β-acetoxy-7α-(oct-7-enyl)estra-1.3.5(10)-trien-3-ol.

To a solution of the preceding estr-4-en-3-one (4.47 g, 10.5 mmol) in150 ml of acetone are added cyclohexene (26.5 ml, 0.26 mol) and CuBr₂(4.7 g, 21.0 mmol).The mixture obtained is stirred vigorously at roomtemperature for 20 hours. More CuBr₂ (7.05 g, 31.6 mmol) is added inthree portions once every three hours. A saturated aqueous solution ofNaHCO₃ is added. The solvent and the excess cyclohexene are evaporated.The residue is diluted with water, and extracted with ethyl acetate. Thecombined organic phases are washed with a saturated aqueous solution ofNaCl, dried over MgSO₄ and evaporated. The residue is purified by silicagel column chromatography (eluent: EtOAc:cyclohenane, 1:9) to providethe desired product (3.76 g, 85%) as a colorless oil.

MS (EI): 424 (100). ¹ H NMR: 0.81 (s, 3H), 0.90-2.35 (m, 24H), 2.05 (s,3H), 2.68 (d, 1H, J=16.5 Hz), 2.85 (dd, 1H, J=4.8, 16.5 Hz), 4.69 (dd,1H, 7.6, 8.8 Hz), 4.89 (m, 1H), 4.95 (m, 1H), 5.78 (m, 1H), 6.53 (d, 1H,J=2.5 Hz), 6.61 (dd, 1H, J=2.5, 8.4 Hz), 7.12 (d, 1H, J=8.4 Hz).

Step 3. Preparation of17β-acetoxy-7α-(8-hydroxyoctyl)estra-1,3,5(10)-trien-3-ol.

To a solution of 17β-acetoxy-7α-(oct-7-enyl)estra-1,3,5(10)-trien-3-ol(0.38 g, 0.90 mmol) in 10 ml of anhydrous THF is added 9-BBN (5 ml, 0.5M solution in THF, 2.5 mmol). The mixture is stirred at room temperaturefor 3 hours. 3 ml of an aqueous solution of KOH (3N) and 3 ml of anaqueous solution of hydrogen peroxide (30%) are added successively. Thereaction medium is stirred for 18 hours then neutralised to pH 7 with anaqueous solution of HCl (1N). The mixture is extracted with ethylacetate. The combined organic phases are washed with a saturated aqueoussolution of NaCl, dried over MgSO₄ and evaporated. The residue ispurified by silica gel column chromatography (eluent: EtOAc:cyclohexane,1:4) to provide the expected diol (0.214 g, 54%) as a colourless oil.

MS (EI): 442 (72), 253 (46), 157 (62). ¹ H NMR: 0.82 (s, 3H), 0.90-2.40(m, 26H), 2.05 (s, 3H), 2.68 (d, 1H, J=16.5 Hz), 2.85 (dd, 1H, J=4.8,16.5 Hz), 3.64 (t, 2H, J=6.5 Hz), 4.70 (t, 1H, J=8.8 Hz), 6.12 (br s,1H), 6.55 (d, 1H, J=2.2 Hz), 6.64 (dd, 1H, J=2.2, 8.4 Hz), 7.13 (d, 1H,J=8.4 Hz).

Step 4. Preparation of17β-acetoxy-3-benzoyloxy-7α-(8-hydroxyoctyl)estra-1,3,5(10)-triene.

An aqueous solution of NaOH (0.75 ml, 1N, 0.75 mmol) is added to asolution of the above diol (214 mg, 0.48 mmol) in acetone cooled to -5°C. To the resulting mixture is added dropwise benzoyl chloride (87 ml,0.75 mmol). The mixture is stirred for 10 minutes at -5° C. 10 ml ofwater and 10 ml of a saturated aqueous solution of NaHCO₃ are added. Themixture is extracted with ethyl acetate. The combined organic phases arewashed with a saturated aqueous solution of NaCl, dried over MgSO₄ andevaporated. The residue is purified by silica gel column chromatography(eluent: EtOAc:cyclohexane, 1:2) to provide the expected product (242mg, 92%) as a colorless oil.

MS (EI): 546 (33), 486 (30), 441 (21), 105 (100). ¹ H NMR: 0.82 (s, 3H),0.90-2.50 (m, 26H), 2.06 (s, 3H), 2.75 (d, 1H, J=16.5 Hz), 2.92 (dd, 1H,J=2.3, 16.5 Hz), 3.60 (t, 2H, J=6.5 Hz), 4.69 (t, 1H, J=8.8 Hz), 6.91(d, 1H, J=2.3 Hz), 6.96 (dd, 1H, J=2.3, 8.4 Hz), 7.34 (d, 1H, J=8.4 Hz),7.50 (m 2H), 7.61 (m, 1H), 8.19 (m, 2H).

Step 5. Preparation of17β-acetoxy-3-benzoyloxy-7α-(8-methanesulfonyloxyoctyl)estra-1,3,5(10)-triene.

To a solution of17β-acetoxy-3-benzoyloxy-7α-(8-hydroxyoctyl)estra-1,3,5(10)-triene (242mg, 0.44 mmol) in 5 ml of CH₂ Cl₂ cooled to 0° C. is added triethylamine(92 ml, 0.66 mmol). Methanesulfonyl chloride (38 ml, 0.48 mmol) is addeddropwise. The mixture is stirred at 0° C. for 30 minutes, then at roomtemperature for 30 minutes. The solvent is evaporated, the residue ismixed with water, then extracted with ethyl acetate. The combinedorganic phases are washed with a saturated aqueous solution of NaCl,dried over MgSO₄ and evaporated to dryness to provide a colorless oilwhich contains essentially the desired product (0.53 g). This oil isused directly in the next step.

¹ H NMR: 0.82 (s, 3H), 0.90-2.50 (m, 26H), 2.05 (s, 3H), 2.75 (d, 1H,J=16.5 Hz) 2.92 (dd, 1H, J=4.8, 16.5 Hz), 3.00 (s, 3H), 4.21 (t, 2H,J=6.6 Hz), 4.76 (t, 1H, 8.7 Hz), 6.90 (d, 1H, J=2.40 Hz), 6.98 (dd, 1H,J=2.4, 8.4 Hz), 7.35 (d, 1H, J=8.4 Hz), 7.50 (m, 2H), 7.61 (m, 1H), 8.20(m, 2H).

Step 6. Preparation ofN-{8-[17β-acetoxy-3-benzoyloxyestra-1,3,5(10)-trien-7α-yl]octyl}-3,3-dimethyl-7-nitroisoselenazoline.

Following the method of alkylation of3,3-dimethyl-7-nitrobenziso-selenazoline described in step 1 of Example8, the expected product is obtained as a deep red solid from thepreceeding mesylate with a yield of 61% [calculated in two steps from17β-acetoxy-3-benzoyloxy-7α-(8-hydroxyoctyl)estra-1,3,5(10)-triene].

MS (CI, tBuH): 787 (100). ¹ H NMR: 0.84 (s, 3H), 1.53 (s, 6H), 2.06 (s,3H), 0.90-2.50 (m, 26H), 2.80 (m,4H), 4.71 (t, 1H, J=7.8 Hz), 6.92 (d,1H, J=2.3 Hz), 6.97 (dd, 1H, J=2.3, 8.4 Hz), 7.31 (m, 3H), 7.50 (m, 2H),7.60 (m, 1H), 8.18 (m, 3H).

Step 7: Preparation ofN-{8-[3.17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline.

N-{8-[17β-acetoxy-3-benzoyloxyoestra-1,3,5(10)-trien-7α-yl]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline(115 mg, 0.15 mmol) is dissolved in 2 ml of THF and 1 ml of methanol. Tothe obtained mixture is then added an aqueous solution of NaOH (1 ml,1N, 1.0 mmol). The reaction medium is stirred at room temperature for 22hours, then neutralized with an aqueous solution of HCl (1N). Themixture is extracted with ethyl acetate. The combined organic phases arewashed with a saturated aqueous solution of NaCl, dried over MgSO₄ andevaporated. The residue is purified by silica gel column chromatography(eluent: EtOAc:cyclohexane, 1:3) to provide the expected product (95 mg,94%) as a deep red solid.

M. Pt.: 95° C. MS (EI): 640 (18), 625 (100), 395 (31), 278 (62). ¹ HNMR: 0.78 (s, 3H), 1.55 (s, 6H), 0.90-2.35 (m, 26H), 2.78 (m, 4H), 3.75(t, 1H, J=8.4 Hz), 6.54 (d, 1H, J=2.6 Hz), 6.62 (dd, 1H, J=2.6, 8.4 Hz),7.13 (d, 1H, J=8.4 Hz), 7.30 (dd, 1H, J=1.7, 7.4 Hz), 7.36 (t, 1H, J=7.4Hz), 8.17 (dd, 1H, J=1.7, 7.4 Hz).

Example 6N-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline

Step 1: Preparation of8-(17β-acetoxy-3-benzoyloxyestra-1,3,5(10)-trien-7α-yl)octanoic acid.

To a solution of17β-acetoxy-3-benzoyloxy-7α-(8-hydroxyoctyl)-estra-1,3,5(10)-triene(0.74 g, 1.4 mmol), described in step 4 of Example 5, in 10 ml ofacetone cooled to 0° C. is added dropwise a solution of Jones' Reagent(aqueous solution of chromic acid, 8N, 0.85 ml, 6.8 mmol). Afterstirring for 15 minutes, 0.3 ml of isopropanol is added and the mixtureis evaporated to dryness. Brine is added to the residue. The mixture isextracted with ethyl acetate. The combined organic phases are washedwith a saturated aqueous solution of NaCl, dried over MgSO₄ andevaporated. The residue is purified by silica gel column chromatography(eluent: EtOAc:cyclohexane, 1:1) to provide the expected acid (0.53 g,70%) as a white solid.

MS (CI, t-BuH): 560 (66), 455 (100). ¹ H NMR: 0.84 (s, 3H), 2.07 (s,3H), 0.90-2.50 (m, 26H), 2.76 (d, 1H, J=17.1 Hz), 2.93 (dd, 1H, J=4.3,17.1 Hz), 4.72 (t, 1H, J=8.1 Hz), 6.92 (d, 1H, J=2.3 Hz), 6.97 (dd, 1H,J=2.3, 8.5 Hz), 7.33 (d, 1H, J=8.5 Hz), 7.50 (m, 2H), 7.62 (m, 1H), 8.19(m, 2H).

Step 2: Preparation ofN-{8-[17β-acetoxy-3-benzoyloxyestra-1,3,5(10)-trien-7α-yl]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline.

To a solution of the above acid (220 mg, 0.39 mmol) in 5 ml of CH₂ Cl₂are added sulfonyl chloride (48 ml, 0.66 mmol) and 5 ml of anhydrousDMF. The mixture is stirred at room temperature for 1 hour, heated underreflux for 0.5 hours, then evaporated to dryness. The residue is takenup with 5 ml of CH₂ Cl₂, evaporated again to dryness and then dissolvedin 3 ml of CH₂ Cl₂. The solution obtained is added dropwise, at roomtemperature, to a solution of 3,3-dimethyl-7-nitrobenzisoselenazoline ofExample 1 (86 mg, 0.33 mmol) and triethylamine (70 ml, 0.5 mmol) in 5 mlof CH₂ Cl₂. The mixture is stirred for 1 hour then evaporated todryness. The residue is purified directly by silica gel columnchromatography (eluent: EtOAc:cyclohexane, 1:4) to provide the expectedproduct (265 mg, 84%) as a red solid.

MS (CI, t-BuH): 801 (100), 153 (20), 139 (21). ¹ H NMR: 0.82 (s, 3H),1.82 (br s, 6H), 2.04 (s, 3H), 0.90-2.50 (m, 26H), 2.76 (d, 1H, J=17.1Hz), 2.92 (dd, 1H, J=4.6, 17.1 Hz), 4.69 (dd, 1H, J=7.7, 8.4 Hz), 6.90(d, 1H, J=2.4 Hz), 6.96 (dd, 1H, J=2.4, 8.4 Hz), 7.26-7.42 (m, 3H), 7.48(m, 2H), 7.61 (m, 1H), 8.19 (m, 3H).

Step 3: Preparation ofN-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline.

Following the method described in step 7 of Example 5, theabove-mentioned amide is saponified to provide the expected finalproduct as a red solid with a yield of 79%.

M. Pt.: 128° C. MS (CI, t-BuH): 655 (100), 115 (26). ¹ H NMR 0.77 (s,3H), 0.90-2.50 (m, 32H), 2.53 (br s, 1H), 2.70 (d, 1H, J=17.1 Hz), 2.85(dd, 1H, J=4.3, 17.1 Hz), 3.76 (t, 1H, J=7.9 Hz), 6.02 (br s, 1H), 6.58(d, 1H, J=2.6 Hz), 6.65 (dd, 1H, J=2.6, 8.4 Hz), 7.14 (d, 1H, J=8.4 Hz),7.34 (br d, 1H, J=7.7 Hz), 7.45 (t, 1H, J=7.7 Hz), 8.23 (dd, 1H, J=1.1,7.7 Hz).

Example 7N-{2-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]ethyl}3,3-dimethyl-7-nitrobenzisoselenazoline

Step 1: Preparation ofN-(2-hydroxyethyl)-3,3-dimethyl-7-nitrobenzisoselenazoline.

To a solution of 3,3-dimethyl-7-nitrobenzisoselenazoline (1.03 g, 4mmol) in 2-bromoethanol (20 ml, 280 mmol, 70 eq.) is added in oneportion 1,8-diaza-bicyclo[5.4.0]undec-7-ene, DBU (2.99 ml, 20 mmol, 5eq.). The reaction medium is then heated to 70° C. and stirring iscontinued for 6 hours at this temperature. Initially orange, thesolution progressively turns brown. After having removed the excessbromoethanol by distillation (0.1 mbar, 60° C.), the residue is taken upwith 50 ml of ethyl acetate and extracted with 10 ml of water (twice).After evaporation of the ethyl acetate, the oil obtained is purified bysilica gel column chromatography (eluent: ethyl acetate:cyclohexane, 1:2then 1:1).

The desired compound is obtained with a yield of 84% as brown crystals.

¹ H NMR: 1.52 (s, 6H), 2.5 (m, 1H --OH), 3.04 (t, 2H, J=5.0 Hz), 3.72(m, 2H), 7.32 (m, 2H), 8.16 (dd, 1H, J=1.9, 7.3 Hz). ¹³ C NMR: 25.50,54.48, 62.12, 72.51, 123.90, 127.77, 128.77, 138.34, 144.16, 151.39.

Step 2: Preparation ofN-(2-methanesulfonyloxyethyl)-3,3-dimethyl-7-nitroisoselenazoline.

To a solution of the alcohol, prepared in step 1 above, (0.297 g, 1mmol) in 10 ml of THF containing triethylamine (0.15 ml, 1.1 mmol)cooled to 0-5° C. by an ice bath, is added dropwise methanesulfonylchloride (0.085 ml, 1.1 mmol); the ice bath is removed and stirring iscontinued for 1 hour at room temperature. After the addition of 10 ml ofwater, the reaction medium is extracted with 20 ml of ethyl acetate(twice). The organic phases are combined, washed with 10 ml of asaturated aqueous solution of NaCl, then dried over MgSO₄ before beingevaporated.

After silica gel column chromatography (eluent: ethylacetate:cyclohexane, 1:2) the mesylate (0.36 g, 96%) is obtained asbrown crystals.

¹ H NMR: 1.54 (s, 6H), 3.07 (s, 3H), 3.20 (t, 2H, J=5.5 Hz), 4.36 (t,2H, J=5.5 Hz). ¹³ C NMR: 25.71, 38.09, 52.91, 70.09, 73.14, 124.04,128.10, 128.97, 138.05, 144.49, 150.91.

Step 3: Preparation ofN-{2-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]ethyl}-3,3-dimethyl-7-nitroisoselenazoline.

To a suspension of sodium hydride (8 mg, 60% dispersion in mineral oil,0.2 mmol) in 2 ml of THF, under nitrogen, at room temperature, is addeddropwise a solution of (Z)-1,2-diphenyl-1-(4-hydroxyphenyl)but-1-ene (50mg, 0.167 mmol) in 2 ml of THF. After 1 hour of stirring at roomtemperature, the yellow solution obtained is treated with the mesylatederivative of the selenazoline (76 mg, 0.2 mmol) prepared above. Thereaction mixture is heated under reflux for 48 hours then, after coolingand neutralization with a saturated solution of NH₄ Cl, it is extractedwith 10 ml of ethyl acetate and washed with a saturated solution ofNaCl; the organic phase is dried and then evaporated before beingchromatographed on a silica gel column (eluent: ethylacetate:cyclohexane, 1:9).

The desired compound (70 mg, 72%) is obtained as brown crystals.

MS (EI): 583 (15), 568 (100), 270 (22). ¹ H NMR: 0.94 (t, 3H, J=7.4 Hz),1.57 (s, 6H), 2.48 (q, 2H, J=7.4 Hz), 3.27 (t, 2H, J=5.8 Hz), 4.24 (t,2H, J=5.8 Hz), 6.62 (d, 2H, J=8.9 Hz), 6.84 (d, 2H, J=8.9 Hz), 7.23 (m,12H), 8.80 (dd, 1H, J=1.8, 7.3 Hz).

Example 8N-{8-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline

Step 1: Preparation ofN-(8-hydroxyoctyl)-3,3-dimethyl-7-nitrobenzisoselenazoline.

A mixture of 3,3-dimethyl-7-nitrobenzisoselenazoline (2.57 g, 10 mmol),8-bromo-octanol (3.4 ml, 20 mmol), tetra-n-butylammonium iodide (3.69 g,10 mmol) and bis(N-dimethylamino)naphthalene (3.20 g, 15 mmol) isstirred, at 110° C. for 12 hours. After cooling and the addition of 20ml of water, the resulting solution is extracted with 40 ml of ethylacetate (twice). The organic phases are combined, washed with 20 ml of asaturated solution of NaCl, dried over MgSO₄ and evaporated.

Silica gel column chromatography (eluent: ethyl acetate:cyclohexane,1:3) permits obtaining a very viscous brown oil (2.11 g, 55%).

¹ H NMR: 1.20-1.70 (m, 19H), 2.80 (m, 2H), 3.61 (s, 2H, J=6.5 Hz), 7.31(m, 2H), 8.15 (dd, 1H, J=1.6, 7.4 Hz).

Step 2: Preparation ofN-{8-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline.

To a solution of (Z)-1,2-diphenyl-1-(4-hydroxyphenyl)but-1-ene phenate(64 mg, 0.21 mmol) is added, at room temperature and dropwise, asolution of N-(8-hydroxyoctyl)-3,3-dimethyl-7-nitrobenzisoselenazolinemesylate (130 mg, 0.28 mmol), prepared in step 2 of Example 7. Thereaction mixture is held under reflux of THF for 36 hours then treatedaccording to the protocol of step 3 of Example 7.

After chromatography (eluent: ethyl acetate: cyclohexane, 1:9 then 1:5),the expected product (112 mg, 80%) is formed as brown crystals.

¹ H NMR of the mesylate: 1.25-1.80 (m, 12H), 1.53 (s, 6H), 2.82 (m, 2H),2.99 (s, 3H), 4.24 (t, 2H, J=6.3 Hz), 7.33 (m, 2H), 8.19 (dd, 1H, J=1.5,7.0 Hz). MS (EI) of the selenazoline: 668 (32), 493 (85), 305 (100). ¹ HNMR of the selenazoline: 0.94 (t, 3H, J=7.5 Hz), 1.25-1.80 (m, 12H),1.43 (s, 6H), 2.49 (q, 2H, J=7.5 Hz), 2.83 (m, 2H), 4.08 (t, 2H, J=6.1Hz), 6.64 (d, 2H, J=8.5 Hz), 6.87 (d, 2H, J=8.5 Hz), 7.10-7.05 (m, 12H),8.20 (dd, 1H, J=1.7, 7.2 Hz).

Example 9N-{2-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]acetyl}-3,3-dimethyl-7-nitrobenzisoselenazoline

Step 1: Preparation ofN-(chloroacetyl)-3,3-dimethyl-7-nitrobenzisoselenazoline.

To a solution of 3,3-dimethyl-7-nitrobenzisoselenazoline (1.28 g, 5mmol), in 20 ml of anhydrous THF, containing triethylamine (0.83 ml, 6mmol), cooled to 5° C. by an ice bath, is added dropwise chloroacetylchloride (0.48 ml, 6 mmol). The dark brown reaction medium lightensrapidly, becoming luminous orange; as soon as the addition of the acidchloride is complete, a considerable precipitate, corresponding totriethylammonium chloride, appears. The amide formation reaction isexothermic. The ice bath is taken away and stirring is continued forabout 1 hour at room temperature. After the addition of 20 ml of waterand 20 ml of ethyl acetate, followed by separation, the organic phase iswashed with 10 ml of a saturated aqueous solution of NaCl, then driedover MgSO₄ and evaporated.

After silica gel column chromatography, the desired amide (1.6 g, 97%)is obtained as very bright orange crystals.

¹ H NMR: 1.89 (s, 6H), 4.14 (br s, 2H), 7.48 (m, 2H), 8.26 (dd, 1H,J=1.7, 7.3 Hz).

Step 2: Preparation ofN-{2-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]acetyl}-3,3-dimethyl-7-nitrobenzisoselenazoline.

To a solution of (Z)-1,2-diphenyl-1-(4-hydroxyphenyl)but-1-ene phenate(150 mg, 0.5 mmol) is added a solution ofN-(chloroacetyl)-3,3-dimethyl-7-nitrobenzisoselenazoline (111 mg, 0.33mmol) in THF and tetra-n-butylammonium iodide (92 mg, 0.25 mmol). Thereaction mixture is heated under reflux for 1 hour , then treatedfollowing the operatory conditions described in step 3 of Example 7.

The desired amide is obtained with a yield of 95% (188 mg) as orangecrystals, after silica gel column chromatography (eluent: ethylacetate:cyclohexane, 1:10 then 1:5).

MS (EI): 598 (100), 313 (39), 207 (22), 129 (27). ¹ H NMR: 0.82 (t, 3H,J=7.5 Hz), 1.84 (s, 6H), 2.46 (q, 2H, J=7.5 Hz), 4.60 (br s, 2H), 6.62(d, 2H, J=8.9 Hz), 6.73 (d, 2H, J=8.9 Hz), 7.0-7.55 (m, 12H), 8.25 (d,1H, J=8.0 Hz).

Example 10N-{8-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline

Step 1: Preparation ofN-(8-Bromooctanoyl)-3,3-dimethyl-7-nitrobenzisoselenazoline.

The method is identical to that used in step 1 of Example 9. The desiredamide is obtained, after silica gel column chromatography (eluent: ethylacetate:cyclohexane, 1:9 then 1:5) with a yield of 95% as bright orangecrystals.

¹ H NMR: 1.38-1.91 (m, 10H), 2.3-2.6 (br m, 2H), 3.39 (t, 2H, J=13.6Hz), 7.38 (m, 2H), 8.21 (dd, 1H, J=1.1, 9.2 Hz).

8-bromooctanoyl chloride was prepared by heating 1 equivalent of thecorresponding acid under reflux of benzene in the presence of sulfonylchloride (2 equivalents) for 15 hours. After evaporation of the solventsfollowed by a second drying under a reduced pressure of 0.01 mbar, theacid chloride is used without further purification; it is a colourlessliquid.

Step 2:N-{8-[4-(1,2-diphenylbut-1-en-1-yl)phenoxy]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline.

A solution of (Z)-1,2-diphenyl-1-(4-hydroxyphenyl)but-1-ene phenate (100mg, 0.32 mmol) in 2 ml of THF, at room temperature, is added a solutionof N-(8-bromooctanoyl)-3,3-dimethyl-7-nitrobenzisoselenazoline(100 mg,0.22 mmol) in 2 ml of THF then tetra-n-butylammonium iodide (80 mg, 0.22mmol).

The resulting solution is held under reflux for 2 hours.

After the usual operations of treatment of the reaction medium describedin the step 3 of Example 7, the desired derivative is obtained aftersilica gel column chromatography (eluent: ethyl acetate:cyclohexane, 1:9then 1:5), as orange crystals (140 mg, 93%).

MS (EI): 682 (100), 665 (22), 423 (38), 300 (45), 243 (47). ¹ H NMR:0.92 (t, 3H, J=7.7 Hz), 1.4-1.9 (m, 12H), 1.43 (s, 6H), 2.46 (q, 2H,J=7.7 Hz), 3.81 (t, 2H, J=13.1 Hz), 6.51 (d, 2H, J=8.3 Hz), 6.78 (d, 2H,J=8.3 Hz), 7.10-7.50 (m, 12H), 8.23 (d, 1H, J=7.3 Hz).

Example 11 N-ethyl-3,3-dimethyl-7-nitrobenzisoselenazoline

According to the general protocol for the alkylation of the selenazolinedescribed in step 1 of Example 7, theN-ethyl-3,3-dimethyl-7-nitrobenzisoselenazoline is obtained, aftersilica gel chromatography (eluent: ethyl acetate:cyclohexane, 1:9), witha yield of 56%, as a brown solid.

MS (EI): 286 (15), 271 (100), 115 (19). ¹ H NMR: 1.16 (t, 3H, J=7.0 Hz),1.54 (s, 6H), 2.85 (q, 2H, J=7.0 Hz), 7.28 (dd, 1H, J=1.8, 7.3 Hz), 7.34(t, 1H, J=7.3 Hz), 8.14 (dd, 1H, J=1.8, 7.3 Hz).

EXAMPLES OF APPLICATIONS

The operating protocols described hereafter are some non limitingexamples of the implementation of the tests of activity of the compoundsof the invention.

Example 12

MEASUREMENT OF THE GLUTATHIONE OXIDASE ACTIVITY OF COMPOUNDS OF GENERALFORMULA IA

To 1.5 ml of 50 mM HEPES buffer, pH 7.3, containing 2.47 mM of reducedglutathione (GSH), 0.32 mM of nicotinamide adenine dinucleotidephosphate (NADPH), and 1.23 units/ml of glutathione disulfide reductase(GR), at 37° C., are added, in the following order:

320 μl of 50 mM HEPES buffer, pH 7.3, containing 0.1 mM of DTPA,pre-equilibrated at 37° C.

30 μl of a 5 mM ethanolic mother-solution of the compound under test or30 μl of absolute ethanol (blank). Each compound is tested at a finalconcentration of 81 μM.

The final reaction volume is 1850 μl.

The glutathione oxidase activity is assayed at 37° C. by measuring thereduction in absorbance at 340 nm over 5 minutes. The said initialenzymatic rate or activity is proportional to the slope of the plot ofabsorbance against time.

The catalytic activity for oxygen reduction in the compounds under testcorresponds to the rate of consumption of NADPH. When this rate issignificantly greater than that of the control, the correspondingglutathione oxidase activity can be verified directly by the measurementof the kinetics of the consumption of dissolved oxygen with the aid of aClark electrode.

The results for the glutathione oxidase activity obtained are shown inTable 1.

After examining these results, it is noted that the compounds of generalformula IA described in the present invention catalyse the oxidation ofNADPH in the presence of glutathione (GSH) and glutathione disulfidereductase.

Furthermore, the effects of superoxide dismutase (SOD), catalase,iodoacetamide (IAA) and Se-GPx on the glutathione oxidase activity ofthe tested compounds have been studied.

To 1.5 ml of HEPES buffer, pH 7.3, containing reduced glutathione (GSH),2.51 mM of nicotinamide adenine dinucleotide phosphate (NADPH) and 1.23units/ml of glutathione disulfide reductase GR, at 37° C., are added inthe following order:

the necessary and sufficient quantity, variable according to the case,of 50 mM HEPES, pH 7.3, containing 0.1 mM of DTPA, pre-equilibrated at37° C.; the final reaction volume being 1850 μl.

then:

either 100 μl of a solution of 1850 units/ml of SOD in water ofultrapure quality,

or 100 μl of a solution of 1850 units/ml of catalase in water ofultrapure quality and 100 μl of a solution of 1850 units/ml of SOD inwater of ultrapure quality,

or 150 μl of a 6.2 mM solution of iodoacetamide in 50 mM HEPES buffer,pH 7.3, containing 0.1 mM DTPA,

or 100 μl of a solution of 10 units/ml of glutathione peroxidase Se-GPxin 50 mM HEPES buffer, pH 7.3, containing 0.1 mM of DTPA,

or 100 μl of a solution of 1850 units/ml of SOD in water of ultrapurequality, and 100 μl of a solution of 10 units/ml of glutathioneperoxidase Se-GPx in 50 mM HEPES buffer, pH 7.3, containing 0.1 mM ofDPTA.

and lastly the addition of:

30 μl of a 5 mM ethanolic mother-solution of the compound under test.

The glutathione oxidase activity is assayed at 37° C. by monitoring thedecrease in the absorbance at 340 nm over 15 minutes. The said initialenzymatic rate or activity is proportional to the slope of the plot ofabsorbance against time.

The consumption of NADPH has been calculated from the slopes of thecurves obtained (OD/minute): ##EQU1## where: Vt=total volume of thereaction=1850 μl

ε=molar extinction coefficient of NADPH=6.22×10⁶. M⁻¹.cm⁻¹

The results obtained are shown in Table 1. They are expressed in nmolesof NADPH oxidized per minute.

After an examination of the results, it is noted that none of theeffectors tested have any effect on the GSH oxidase activity of themolecule under test, neither separately nor in combination.

                  TABLE 1                                                         ______________________________________                                        Effect of SOD, catalase, SeGPx and IAA on the                                  GSH oxidase activity                                                                     nmole NADPH oxidized/min                                                                       SD       N                                       ______________________________________                                        Bxt51062 + GSH +                                                                          77.17            ±6.5% 4                                         GR-NADPH                                                                      +SOD 78.78 ±4.9% 4                                                         +SOD and CAT 79.29 ±6.6% 3                                                 +IAA 76.25 ±4.3% 2                                                         +Se-GPx 80.61 ±1.2% 3                                                      +Se-GPx and SOD 78.45 ±1.5% 2                                            ______________________________________                                         * SD: Standard deviation                                                      * N: Number of tests                                                     

It is thus noted that the compounds of the invention possess asignificant and specific pro-oxidizing activity. From this fact, theyare useful as active ingredients in pharmaceutical compositionspossessing a pro-oxidizing activity and in particular for destroyingcancer cells.

Example 13

MEASUREMENT OF THE REDUClNG ACTIVITY BY MONO-ELECTRONIC TRANSFER.

The ability of the molecules of general formula IA in the presentinvention to catalyse the reduction of an oxidizing entity bymonoelectronic transfer in the presence of glutathione GSH, isdemonstrated by spectrophotometrically monitoring the reduction offerric cytochrome c to ferrous cytochrome c, at pH 7.3 and at 37° C., asa function of time.

The reaction medium is made up of:

700 μl of 50 mM HEPES buffer (pH 7.3), pre-incubated at 37° C.,containing 100 μM of ferric cytochrome c, 0.1 mM of DTPA, 10 μg/ml ofSOD and 110 U/ml of catalase.

the necessary and sufficient quantity, variable according to the case,of 50 mM HEPES buffer, pH 7.3, containing 0.1 mM of DTPA,pre-equilibrated at 37° C., the final reaction volume being 1 ml.

then:

either 100 μl of a solution containing 2.6 mM of NADPH and 10 units/mlof glutathione disulfide reductase in 50 mM HEPES buffer, pH 7.3,containing 0.1 mM of DTPA.

or 100 μl of a 100μM ethanolic solution of the compound under test,

or 100 μl of a 10 mM glutathione GSH solution in 50 mM HEPES buffer, pH7.3, containing 0.1 mM of DTPA.

or 100 μl of a 100μM ethanolic solution of compound under test and 100μl of a 10 mM solution of glutathione GSH in 5 mM HEPES buffer, pH 7.3,containing 0.1 mM of DTPA.

or 100 μl of a 100 μM ethanolic solution of the compound under test and100μl of a solution containing 2.6 mM of NADPH and 10 units/ml ofglutathione disulfide reductase in 50 mM HEPES buffer, pH 7.3,containing 0.1 mM of DTPA.

or 100 μl of a 100 μM ethanolic solution of the compound under test and100 μl of a solution containing 2.6 mM of NADPH and 10 units/ml ofglutathione disulfide reductase in 50 mM HEPES buffer, pH 7.3,containing 0.1 mM of DTPA and 100 μl of a 10 mM solution of glutathioneGSH in 50 mM HEPES buffer, pH 7.3, containing 0.1 mM of DTPA.

In every case, the last addition is that of the solution of the compoundunder test.

The increase in absorbance at 550 nm is then measured over 15 minutes,at 37° C.

The rate of formation of reduced (ferrous) cytochrome C is proportionalto the slope of the plot of absorbance against time. The kinetics ofreduced cytochrome C formation is given, with the proviso that theextinction coefficient is 2.1×10⁻⁴ M⁻¹.cm⁻¹ at 550 nm, in FIG. 2.

The results obtained demonstrate that the compounds of general structureIA described in the present invention catalyse the one-electronreduction of molecules which belong to redox couples whose reducingpotential is thermodynamically greater than or equal to that ofcytochrome C, in the presence of glutathione GSH and glutathionedisulfide reductase. Given that these compounds, taken separately, donot reduce ferric cytochrome c, this means that the presence ofglutathione GSH at the same time as glutathione disulfide reductase isrequired for the reducing activity of these compounds.

These results further confirm that the compounds of the inventionpossess a significant pro-oxidizing activity, and from this fact, theyare useful as active ingredients in pharmaceutical compositionspossessing a pro-oxidizing activity and in particular for destroyingcancerous cells.

Example 14

CYTOTOXIClTY OF COMPOUNDS OF GENERAL STRUCTURE IA ON HL60 CELLS.

Human leukemia cells HL60 are cultivated at 37° C. in 6-hole plates orin Petri dishes (diameter 35 mm) in an atmosphere of a gaseous mixtureof 95% air and 5% CO₂, saturated with water.

The culture medium is constituted by RPMI 1640 medium, pH 7.4,containing 20% of foetal calf serum (FCS), 10 mM HEPES, 1 mM pyruvate, 4mM of L-glutamine, 100 U/ml of penicillin and 100 μg/ml of streptomycin.Before use, the cells are centrifuged at 1500 rpm for 10 minutes at roomtemperature. The cellular pellet is resuspended in the RPMI-20% FCSmedium in order to obtain a density of 7.10⁵ cells/ml.

The compounds of general structure IA described in the present inventionare solubilised at 20 mM in absolute ethanol and diluted in the RPMI-20%FCS culture medium. The final percentage of ethanol in the reactionmedium is 0.8% (v/v). The molecules are studied at the followingconcentrations: 80; 40; 20; 10; 5.2; 1.25; 0.62 and 0.31 μM. Twocontrols are carried out, in the presence and in the absence of ethanolrespectively, using 100 μl of cell suspension at 7.10⁵ cells/mlincubated with 100 μl of RPMI-20% FCS medium ±0.8% of ethanol (v/v). 100μl of an ethanolic solution of the compound under test are added to 100μl of the suspension of HL60 cells at 7.10⁵ cells/ml and the reactionmedium thus constituted is incubated for either 24 or 48 hours at 37°C., in the same culture conditions as those described above. From theseincubations, the viability of the cells is measured using3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT. MTTis metabolised by mitochondrial dehydrogenases into an insoluble dyewhich is therefore exclusively visualised in living cells.

MTT Test: To 200 μl of cellular suspension, obtained above, are added 50μl of a solution of 5 mg/ml of MTT in PBS buffer. After 4 hours ofincubation at 37° C., the medium is centrifuged for 10 minutes at 3000rpm. The supernatant is removed, and 100 μl of DMSO is added to the cellpellet. This suspension is left to incubate for 10 minutes with stirringat 37° C. The developed color is measured at 550 nm against DMSO. Theoptical density OD=f(living cells) can then be plotted as a function oftime.

The results are shown in FIGS. 3 and 4.

These results demonstrate that the compounds of general formula IAdescribed in the present invention are taken up by the HL60 tumor cellsand kill such cells at micromolar concentrations.

Example 15

CYTOTOXIClTY OF COMPOUNDS OF GENERAL STRUCTURE IA ON MCF-7 CELLS.

The MCF-7 cells from a breast cancer of human origin are cultivated, inan atmosphere of a gaseous mixture of 95% air and 5% CO₂ , saturatedwith water, two days before the test, in order to be in a growth phaseduring the toxicity test. The cells are trypsinized and are collected ina RPMI 1640 medium containing 10% FCS, 10 mM HEPES, 1 mM pyruvate, 4 mML-glutamine, 100 U/ml penicillin, 100 μg/ml streptomycin, in order to becentrifuged at 1,500 rpm for 10 minutes. The cell pellet is resuspendedin the same medium in order to obtain a cell density of 30,000cells/cm².

The compounds of general structure IA described in the present inventionare solubilised at 10 mM in absolute ethanol and diluted in RPMI-10% FCSculture medium, the final volume of ethanol in the reaction medium is0.5% (v/v). The molecules are studied at the following concentrations:50; 25; 12.5; 6.25; 3.125; 1.562; 0.781; 0.391 and 0.195 μM. Twocontrols are carried out, in the presence and in the absence of ethanolrespectively, using 100 μl of cell suspension of 30,000 cells/cm²incubated with 100 μl of RPMI-10% FCS medium and ±0.5% of ethanol (v/v).

Before starting the study, the cells are rinsed with PBS buffer whichcontains neither calcium nor magnesium. The cells are then incubatedwith 200 μl of compound under test, or with the medium containing or not0.5% of ethanol (controls) for either 24 or 48 hours under an atmosphereof a gaseous mixture of 95% air and 5% CO₂, saturated with water, at 37°C., then submitted to the viability test with MTT according to thefollowing protocol.

To 200 μl of culture medium are added 50 μl of MTT at 5 mg/ml in PBSbuffer. After 4 hours of incubation at 37° C., the plate is centrifugedfor 10 minutes at 3,000 rpm. The supernatant is removed and the cellpellet is resuspended in 100 μl of DMSO. This is left to incubate for 10minutes with stirring at 37° C. The coloration developed is measured at550 nm against DMSO. The optical density OD=f(living cells) can then beplotted as a function of time.

The results are shown in FIGS. 5, 6, 7 and 8 as well as in Table 2.

The examination of the results demonstrate that the compounds of theinvention are taken up by the MCF-7 tumor cells and kill such cells atmicromolar concentrations.

                  TABLE 2                                                         ______________________________________                                        % OF MORTALITY OF THE MCF-7 CELLS                                                  Bxt-51062  Bxt-57001  Bxt-57007                                                                              Bxt-57004                                 μm                                                                              24 h    48 h   24 h  48 h 24 h  48 h 24 h  48 h                          ______________________________________                                        50   100     100    99.78 100  40.78 46.33                                                                              100   100                             25 100 100 99.07 99.82 36.62 46.77 92.8 88.41                                 12.5 100 100 75.267 58.51 28.62 44.63 79.84 75.79                             6.25 100 100 54.98 41.24 19.36 33.22 73.31 76.42                              3.125 70.11 82.97 23.93 23.26 13.32 18.72 71.17 69.08                         1.562 42.71 58.51 29.45 20 12.95 25.1 59.35 60.45                             0.781 23.58 32.51 16.86 0 8.39 14.2 34.91 38.64                               0.391 0 0 0 0 1.02 8.42 3.19 12.77                                            0.195 0 2.22 0 0 0 1.07 0 17.42                                             ______________________________________                                         ##STR8##

    __________________________________________________________________________    Ex. Structures    Ex.                                                                              Structures                                               __________________________________________________________________________      1                                                                                                  7                                                                             #STR9##                                                   - 4                                                                                               8S R10##                                                                      #STR11##                                                  - 3                                                                                               9S R12##                                                                      #STR13##                                                  - 2                                                                                               10 R 4##                                                                      #STR15##                                                  -  ,1 7 ,1 Step 1                                                                                 5S R16##                                                                      #STR17##                                                  - 11                                                                                              6S R18##                                                                     ##STR19##                                               __________________________________________________________________________

What is claimed is:
 1. A organoselenium compound of formula (I): ##STR20## wherein: R¹ is selected from a group consisting of: hydrogen; C₁ -C₆ alkyl; ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect;R² is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl; ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect; R³ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl; ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; --COR⁸ ; --COOR⁸ ; --CONH₂ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect; R⁴ is selected from the group consisting of: --NO₂ ; --NO; --CN; --COOR⁹ ; --SO₃ R⁹ ; --CONR⁹ R¹¹ and --SO₂ NR⁹ R¹¹ ; R⁵ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl; --COR⁸ ;--COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; --(CH₂)_(p) Vect; --N⁺ R¹¹ ₃ Y⁻ ; --SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ; X is selected from the group consisting of: (CR⁶ R⁷)_(n) ; and CO; R⁶ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl; --COR⁸ ;--COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect; R⁷ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl; --COR⁸ ;--COOR⁸ ; --CONR⁸ R⁹ ; --(CH₂)_(p) R¹⁰ ; and --(CH₂)_(p) Vect; R⁸ is selected from the group consisting of: C₁ -C₆ alkyl; ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; heteroaryl; heteroaryl substituted by one or more identical or different groups selected from: C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect; R⁹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl; ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; and --(CH₂)_(p) Vect; R¹⁰ is selected from the group consisting of: hydrogen; --N⁺ R¹¹ ₃ Y⁻ ; --SO₃ ⁻ Z⁺ and --CO₂ ⁻ Z⁺ ; R¹¹ is selected from the group consisting of: hydrogen; C₁ -C₆ alkyl; ar(C₁ -C₆)alkyl; ar(C₁ -C₆)alkyl substituted on aryl by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; aryl; aryl sustituted by one or more identical or different groups selected from C₁ -C₆ alkyl, trifluoromethyl, C₁ -C₆ alkoxy, hydroxyl, nitro, amino, C₁ -C₆ alkylamino, di(C₁ -C₆ -alkyl)amino, sulfonyl, sulfonamide, sulfo(C₁ -C₆ -alkyl), --CO₂ H, and --CO₂ --(C₁ -C₆)alkyl; Vect= ##STR21## Y⁻ is the anion of a pharmaceutically acceptable acid; Z⁺ represents the cation of a pharmaceutically acceptable base;n=0 or 1; m=0 or 1; p=2to 10; and their pharmaceutically acceptable salts of acids or bases; with the proviso that only one among R¹ to R³, R⁵ to R⁹ is compulsorily one Vect substituent within each molecule of the general formula I.
 2. A method of treatment selected from a treatment of leukemia and a treatment of breast cancer, comprising administering to a human in need thereof an effective amount of a compound of formula I as defined in claim
 1. 3. The method of claim 2, wherein the organoselenium compound of the formula (I) is included in a pharmaceutical composition in an amount ranging from 0.01 to 5% by weight, advantageously in the range 0.1 to 1% by weight, with respect to the total weight of the final composition.
 4. The method according to claim 2, wherein the organoselenium compound of the formula I is included in a pharmaceutical composition in the form of unit dose in an amount ranging from 1 to 500 mg, optionally in a pharmaceutically acceptable excipient, vehicle or carrier.
 5. An organoselenium compound selected from the group consisting of:N-{8-[3,17β-dihydroxyestra-1,3,5(1 0)-trien-7α-yl]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline of formula: ##STR22## N-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline of formula: ##STR23##
 6. A pharmaceutical composition comprising, as pharmaceutically active compound: N-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline of formula: ##STR24## in a pharmaceutically acceptable excipient.
 7. A pharmaceutically composition comprising, as pharmaceutically active compound,N-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline ##STR25## in a pharmaceutically acceptable excipient.
 8. A method of treatment of leukemia, comprising administering to a human in need thereof an effective amount ofN-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octyl}-3,3 -dimethyl-7-nitrobenzisoselenazoline of formula ##STR26## optionally in a pharmaceutically acceptable excipient.
 9. A method of treatment of leukemia, comprising administering to a human in need thereof an effective amount ofN-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline ##STR27## optionally in a pharmaceutically acceptable excipient.
 10. A method of treatment of breast cancer, comprising administering to a human in need thereof an effective amount ofN-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octyl}-3,3-dimethyl-7-nitrobenzisoselenazoline of formula: ##STR28## optionally in a pharmaceutically acceptable excipient.
 11. A method of treatment of breast cancer, comprising administering to a human in need thereof an effective amount ofN-{8-[3,17β-dihydroxyestra-1,3,5(10)-trien-7α-yl]octanoyl}-3,3-dimethyl-7-nitrobenzisoselenazoline ##STR29## optionally in a pharmaceutically acceptable excipient.
 12. A pharmaceutical composition comprising a compound of formula I in claim 1 together with a pharmaceutically acceptable carrier. 